Wind chill and water pipes

[trader4]

Thank you. Another person who sees the contradiction and that what NOAA says is consistent with what I've been saying.

It doesn't just reflect "feel". Wind taking heat away from a human being is what causes the feeling. It's not some majical effect confined to living things. It's caused by wind removing heat faster with a higher wind speed.

The same exact effect applies to inanimate objects, like a bucket of

75F water placed outside when it's 20F. With a lower windchill number, it's going to freeze faster. Clearly that is an effect.

And, that

It sucks the heat above the air temp out of anything, that is correct. NOAA says it. Therefore Gordon's statement that:

"Wind chill" has no effect on inanimate objects. Period, if I may quote our fearless leader. "

is wrong. His own link from NOAA says so.

A bucket of 75F water placed outside when it's 20F with a windchill of

0F is going to freeze faster than if the windchill is 20F.

A house is going to take more energy to keep warm on a night when it's

20F outside, but the windchill is 0F instead of 20F.

And pipes in a drafty crawlspace are more likely to freeze on that 20F night with a windchill of 0F, instead of 20F.

He won't even address any of those. Instead of manning up and admitting he's wrong, he just keeps digging his hole deeper, like some others. We;ve seen it before

[Ed Pawlowski]

We're talking about dry inanimate objects though. You are posing a different situation entirely. You are in swamp cooler territory.

[Ed Pawlowski]

Sure, but there is nothing here to evaporate.

[Ed Pawlowski]

I think we are confusing definitions. When the weatherman give wind chill or "real feel" temperatures he is talking about how exposed human flesh feels the temperature. Think evaporative cooling.

Drop the word "chill" and I think we can all agree that wind removes heat faster. There is no evaporative cooling, but faster movement of heat energy from the object.

No matter how you term things, it does not change the laws of physics. .

[Ed Pawlowski]

As the temperature differential increases the movement of heat energy speeds up. Increasing the inside temp to 70 will allow more heat to escape into the interior of the wall. Yes, it can help prevent freezing.

[Ed Pawlowski]

Yes, but that is an efect of the wind, not the wind chill the weatherman talks about how we feel in the wind.

No, it shows the effects of wind but has nothing to do with the windchill factor on the 11 o'clock news

[Stormin Mormon]

1. Does wind chill only apply to people and animals?

Yes. The only effect wind chill has on inanimate objects, such as car radiators and water pipes, is to more quickly cool the object to cool to the current air temperature. Object will NOT cool below the actual air temperature. For example, if the temperature outside is -5 degrees Fahrenheit and the wind chill temperature is -31 degrees Fahrenheit, then your car's radiator will not drop lower than -5 degrees F.

+++++++++++++++++++++++++++++++++++++++

With people and pets, we want to keep the core temp at

98.6, much cooler than that will result in hypothermia. Will a low wind chill make for hypothermia faster? I guess yes.

With water lines, we want to keep at or higher than

32F. Will a low wind chill make for frozen pipes faster? I guess yes.

[Vic Smith]

Exactly.

"The NWS Windchill Temperature (WCT) index uses advances in science, technology, and computer modeling to provide an accurate, understandable, and useful formula for calculating the dangers from winter winds and freezing temperatures. The index: ?Calculates wind speed at an average height of five feet, typical height of an adult human face, based on readings from the national standard height of 33 feet, typical height of an anemometer ?Is based on a human face model ?Incorporates heat transfer theory, heat loss from the body to its surroundings, during cold and breezy/windy days ?Lowers the calm wind threshold to 3 mph ?Uses a consistent standard for skin tissue resistance ?Assumes no impact from the sun (i.e., clear night sky)."

So the term "windchill" has been "appropriated" by the NWS for application to human skin. If you want to use it for pipes in an accurate manner, you need to specify type of pipe, heat transfer rate, etc. I'm sure it has been done by engineers who design things where it's relevent. But they don't call it "windchill."

[nestork]

Yes, and I would agree, but the drop below ambient temperature cannot be attributed to wind chill, but to evaporative cooling.

When water evaporates, it absorbs heat. In this case, it would be absorbing heat from the cinder block, and that's what would cause the temperature of the block to dip below ambient.

Evaporative cooling is how a dog's tongue works to cool the blood of the dog, and therefore cool the dog down on a hot day.

[krw]

I don't know if you're just being pedantic, but you're wrong.

[krw]

Well, if you're adding heat to an object, it does affect the equilibrium temperature. That's the whole point of cooling fans.

[krw]

The multiplier may be different but the concept is *exactly* the same.

Nonsense. The slopes may be different but the physics is the same.

[Larry W]

It occurrs to me that if we were all having this conversation live and in real time, within about 15 minutes tops we would all have explained our qualifiers and lack of precision in language and would likely all agree with each other about the effect wind has on the rate of tmeperature change of any object, animate or inaminate.

[gregz]

There is another wind chill factor. When I drove in the desert with no air, it was often cooler to keep most windows closed. Your evaporative system can only produce so much sweat.

Greg

[Stormin Mormon]

I've not had that experience, but it sounds reasonable. I'll remember that for the future.

I've heard that it's wise to have a LOT of drinking water in the vehicle with you. The one time I drove through Nebraska, I was really glad there was other traffic. A town about every

50 miles, that was some wide open space.

[Stormin Mormon]

I'll try not to do that again. Sorry.

[Gordon Shumway]

I had to look up pedantic. No I'm not to both statements.

Thanks for playing.

[Gordon Shumway]

I was getting ready for bed, sitting on the throne and the figurative light bulb came on! I think I have a way to get my point across once and for all.

I'm sure many of us have done some investigation on this topic. We have probably found that the term wind chill was coined by the American geographer Paul A. Siple sometime in 1939.

Let's pretend that we have all gone over to Mr. Peabody's with Sherman and we climb into the WABAC machine and travel back in time before

1939, let's say the roaring '20's. Long before this thing called wind chill existed. Now let's assume one of you, and I believe Stormy was the sinister individual that started this, is worried about his pipes freezing.

We all know wind chill doesn't exist, because Al Capone says it doesn't, so what would make Stormy's pipes freeze then?

[krw]

Then you're simply wrong.

No play.

[trader4]

First, it's not based on "evaporative cooling", at least in the USA. If it were, then it would need to have a component to reflect the moisture in the air. Dry air removes more heat than high humidity air. But windchill here is based on a formula that uses wind speed and temp alone. Hence, that reported windchill index affects inanimate objects too. The question was asked in the following context:

"Tonight in NYS supposed to be 0F, and wind chill -10 or so. Which number is the one which concerns water pipes freezing? "

The answer is both of them. At 0F, it's cold enough to freeze pipes. And depending on where the pipes are, they can be affected by the windchill. Again, just two examples:

A - Pipes are in a cabin with no heat. Do you think the cabin inside temp will be the same overnight as the temp drops without regard to what the windchill is? If the reported windchill was large, would you not agree that the pipes are going to be more likely to freeze?

B - Pipes in a drafty crawlspace.

Then why won't Gordon just admit he's wrong, even after his own reference from NOAA says that inanimate objects can be affected by windchill?

Again, tell that to Gordon. He's the one that said windchill had absolutely no effect on inanimate objects and won't just admit that he's wrong. Apparently you agree he's wrong too.